This blog is dedicated to bringing World War II era documents to the general public, with an overall focus on armoured warfare.
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Monday, 30 June 2014

"Explanatory note on the project for supplementing the KV's armament with rocket artillery.

Over several years, since 1934, NII #3 worked on arming tanks with rockets. Despite several advantages of this type of armament, no real success was achieved, all work was limited to experimental projects and blueprints.

The main advantages of rocket artillery are:

Simplicity of use and production, both of the shell and weapon.

Low weight of the system.

Negligible cost of the launcher.

Lack of recoil or any other forces that happen as a result of using conventional artillery.

Drawbacks include reduced precision and lower muzzle velocity than with conventional artillery.

The conditions of modern war present an artillery system with many tasks. Rocket artillery cannot solve those tasks on its own. A tank armed with only rockets would be infeasible. A rocket launcher should be installed on a tank only as supplemental armament.

The issue of installing supplemental armament on a tank exists as a result of striving to increase the firepower of a tank. Usually, this can be done as a result of increasing the gun's caliber or the amount of shots fired at once (or in a burst). Increasing the caliber results in increased recoil, which impacts the tank's stability, and also in a heavier gun, which decreases the tank's performance. The rate of fire is limited by the crew's physical capacity, which is confined to the cramped fighting compartment. Additionally, in battle, a burst of many shots is often desirable, which cannot be achieved with a conventional gun.

A simple and cheap rocket launcher can be installed on a tank in addition to existing armament, and fire a barrage in any desirable pattern.

In order to develop this theory, a project for additional armament for a KV tank has been developed. The main component is the rocket launcher (fig. 1, 1), a two-level design. Slots (4) are cut in the upper and lower level for the guiding fins of a rocket. Each rocket has two fins per side. The top level rockets (2) lie on top of the guide rail, the lower level rockets (3) hang off it. The rockets and launcher are the 132 mm type, already mastered by our industry. Both sides of the tank (fig. 2) have three of these launchers installed (1), for a total of six rockets (2,3). In total, the tank has 12 rockets. The rockets are contained in armoured casings (4), which have hatches in the rear and front walls (5,6), opened automatically before firing or manually from inside the tank. The front hatch (5) consists of two halves. The launchers are fixed at an angle of 5 degrees, which gives a range up to 1500 meters. The launchers are affixed on three carriers, two near the rocket casing (7), one near the front of the launcher (8). From the sides, the launchers are covered with armoured plates (9).

Firing is performed using a remote control in the radio operator's compartment, on the left side of the hull. The control panel is connected to the electric launcher mechanism by an adapter. The remote allows the launching of a configurable number of rockets per burst (not simultaneously, but with a very short delay, depending on how fast the launcher flywheel is spun, all rockets are launched within one full rotation). The weight of this device is 1500 kg, which should not negatively impact the tank's performance.

Here is data on the rocket artillery mount for the KV tank:

Rocket type: RS-132

Caliber: 132 mm

Rocket length: 1300 mm

Explosive filler: 5 kg

Number of shells: 12

Total explosive: 60 kg

Length of the system: 3000 mm

Weight of the system: 1500 kg

This launcher does not require any special modifications, aside from the removal of extra tanks on the rear of the wing, the use of which in battle conditions is unlikely.

In this way, using a very simple 132 mm x12 rocket launcher, we can increase the firepower of the KV tank without at all weakening its primary armament.

The proposed project was developed by the scientific research department of the academy.

Enough parts have been shipped to us to assemble one rocket launcher system. Everything is ready to equip one of the academy's KV tanks. Approval from GABTU is needed to begin this work.

The 152 mm self propelled howitzer largely fires directly at close ranges, moving in shorts bursts from line to line. In rare cases, the vehicle opens indirect fire. Firing on the move should be seen as a rare case.

Technical requirements

The SPG is produced with minimal changes to existing designs (152 mm ML-20 howitzer, KV-7 tank).

The dimensions of the vehicle should be as close as possible to the dimensions of the KV-1. The increase in height and bore axis height should not be greater than 100 mm.

The mass of the vehicle with crew, ammunition, and a full load of fuel should be within 45-50 tons.

Primary characteristics of the SPG:

Caliber: 152 mm

Vertical range: -2 degrees to 15-20 degrees

Horizontal range: +/- 5-6 degrees

Aiming speed: 30-45 minutes in one rotation of the flywheel

Recoil length: no more than 850 mm

Recoil resistance: no more than 30-35 tons

Maximum rate of fire with correction of aim: 8 RPM

Force on aiming mechanism when vehicle is stopped: no more than 3 kg

Ammunition capacity: 30 shells

Usage requirements

The SPG is serviced by a crew of 6: commander, mechanic-driver, gunner, loader, breech operator, radio operator/machinegunner.

The oscillating armour should allow for easy access to recoil mechanisms.

The gunner's workspace (seat, aiming mechanisms, sight) should be usable freely and allow for convenient and non-exhausting aiming of the howitzer when in place or in motion. The effort required to operate the trigger mechanism should be no greater than 8 kilograms. It is desirable that the trigger mechanism be placed on the handle of the elevation flywheel.

The commander's workspace should be equipped with a stock cupola from the KV-1S.

The howitzer should have a guard rail, a collapsible tray for readying a shot, and a blocking mechanism to prevent firing until loading is completed. When developing the tray, ensure that it is positioned in a way to make loading take the minimum amount of energy.

The ammunition rack should be robust, resistant to deformation, and provide free and comfortable access to ammunition with the goal of maximizing rate of fire.

The placement of ammunition should take into account the actions taken by the loader and breech operator: the loader prepares and places a shell into the breech, the breech operator opens and closes the breech, as well as inserting the propellant into the breech.

The manual extractor, wrenches for installing detonators, and the rammer are secured on the walls of the turret.

Requirements for the turret and its devices

The rear of the turret should have a hatch for the crew, loading ammunition, and emergency ventilation.

The sides of the turret should have ports for firing a pistol and submachinegun, as well as slits for additional observation. The rear wall should have a ball mount for a DT machinegun.

The crew's personal weapons should be kept in a reliable and convenient holder next to their workspaces.

The roof should have a hatch next to the commander's workspace for firing signal flares, and the rear wall should have a hatch suitable for throwing hand grenades through.

The lights within the turret should provide for comfortable gun maintenance and combat action.

Communication is performed through a stock tank radio and a TPU.

The front turret armour should be no less than 90 mm, 50 mm side and rear. The sides should have a slope of 30 degrees from the vertical.

The commander's workspace should allow for convenience when working with a map or a clipboard.

Each crewman should have a comfortable seat for travel and rest. The seats of the loader and breech operator should be folding, and should not constrict their actions in battle.

The inside of the turret should provide storage for a first aid kit, emergency rations, and a supply of drinking water."

On June 30th, 1915, trials of the Killen-Strait tractor, the basis of the first ever tank, were carried out at the Wormwood-Scrubs proving grounds.

The Killen-Strait farm tractor was produced in America since 1910. A unique feature was the presence of three tracks. The front track was for steering, and the two rear ones for propulsion. The tracks were also unusual. They were composed of hardwood and held together with chains. In order to reduce the amount of wear, the working surface of the tracks was covered in metal sheets.

The Killen-Strait possessed respectable maneuverability and off-road performance. The tilted rear tracks allowed it to back up over obstacles impassable for other tractors that were considered as a base for tanks. Killen-Strait's performance was noticed by Colonel Crompton, the representative from the Committee of Land Ships (an organization participating in the creation of first British tanks).

Sadly, trials showed that the tank cannot be used as a base for a viable prototype. It was too light to tear barbed wire, and had to cut through them, which took more time and could not always be attempted. Aside from that, the hull of the Delano-Belleville armoured car on top of its chassis made the vehicle too tall, and an easy target for enemy gunners.

Despite the fact that the tank was not mass produced, it remains in history as the very first tank, preceding the Little Willie or the MkI.

On June 27th, 1931, the USSR started trials of an experimental medium tank designed by the German engineer Eduard Grotte.

E. Grotte was the head of a group of engineers from Germany that arrived in the USSR in March of 1930. The group was tasked with the development of a 20-ton tank armed with a 76 mm gun and a 37 mm gun, as well as machineguns. A special design bureau was created at the Bolshevik factory for this project, composed of the Germans and young Soviet engineers.

The result was the two-turreted medium TG-1 tank (Tank Grotte). For its time, the vehicle was very novel. It was the first domestic vehicle to have a fully welded turret and hull. The armour was sloped. The gearbox allowed same speed for moving forward and backward. The tank was controlled not with levers, but with a joystick, like a plane. Due to the pneumatic power steering, the driver's job was easier. The suspension was composed of five road wheels per side, 4 return rollers, an idler, and a rear drive wheel, and had a three layer shock absorber system for smooth driving.

The TG-1 has the most powerful tank gun for its time, the A-19 76.2 mm gun designed by Pavel Syachintov. A 37 mm PS-1 gun and five machineguns were used as auxiliary weapons. The armament was placed in three layers to ensure massed five in all directions.

With all its advantages, the Grotte tank never made it to production. All the novelties put into the design led to an unpalatable cost of production, and Soviet industry in the 1930s could not produce components of needed quality. As a result, the tank was unreliable.

Grotte left the USSR in 1933.

Thanks to the TG-1 project, valuable experience was gained, which was later used when designing domestic tanks. The famous Soviet tank engineer Nikolai Vsevolodovich Barykov started his career under Grotte's leadership.

Saturday, 28 June 2014

I have come across some photos from the inside of Kubinka's IS-7, some of which show the plaques on the automatic loader well enough to read. They are instructions on how to operate it, unsurprisingly.

"[painted over]

Before turning on, inspect the mechanism.

Do not grab the conveyor chain when the mechanism is on.

Do not bend into the loading area when the mechanism is on.

Make sure the gun returns to the loading angle (0 degrees +/- 1 degree) and that that loading tray is up against the breech.

If the automatic loader fails to load fully, switch to manual loading."

"Instructions

Remove [illegible] from travel position and [illegible] grips [illegible]

Turn on the electric power supply to the mechanism.

Turn on manual controls and move the rammer chain to the initial position. Turn on automatic controls.

Open the breech.

Roll a shell on the conveyor.

Stop the upper stopper of the conveyor tray and lower it to the loading line.

Friday, 27 June 2014

Army parades are a pretty big deal. You have to make sure everything happens absolutely perfectly, and that takes a lot of preparation. Even something as mundane as a track link has to be looked over.

"For four high-speed BT-7 tanks participating in the May 1st parade, issue 8 small-link assembled tracks, tested at the factory. Send the tracks to military warehouse #404, making sure they arrive no later than April 1st, 1940."

"Act #010 on April 6th, 1940
Composed by representatives:

From the customer:

Military Engineer 3rd grade comrade G.A. Alekseev

From plant #540 QA:

comrade Povkhovtsev

From plant #540:

Senior Engineer V.N. Vasiliev

Senior Engineer I.F. Nastek

to signify that plant #540 produced and tested special 4 track sets. The conditions of testing were as follows:

Driving on a stone road for 20 km at the average speed of 50-55 kph.

After 20 km, 3 braking procedures were performed from ful speed at 3rd gear (1800 RPM) until full stop. The braking path was 15-18 meters long.

Each track in total travelled on a road for 40 km, including 20 km in city driving conditions.

Afterwards, the tracks were disassembled, and after cleaning and washing, each track link was inspected with a 3x magnifying glass. Track links without cracks or other defects affecting robustness were deemed acceptable and marked with green or red paint. From those track links, 4 sets of tracks were assembled, including 8 flat tracks and 8 tracks with horns. The track pins were splinted anew. The tracks were accepted by QA and sealed. Each track has a mark /0/ on the end."

"To the Deputy Commander of the Armoured and Motorized Forces of the Leningrad Front, Major-General comrade Bolotnikov

I present to you a report on the performance of the 16th, 98th, 122nd, and 124th Tank Brigades over the month of March of 1942.

The conditions faced during the month of March fully correspond to those faced in February. All experience gained in February was applied and proven in battle by tank units in March. The following needs to be said regarding combat actions for March.

1. Combat actions were organized by brigade headquarters and commanders more thoroughly. The commanders of the 124th TBr considered the deficiencies in planning during February, and made every attempt to not let them happen again in March.

The template for controlling the battle, passed on to brigades by the Army Armoured Forces HQ was applied in practice, using all types of communication: radio, telephone, radio armoured cars, couriers, and observers, and fully proved itself. However, as a rule, there was not enough time to carefully plan a battle down to the details.

A limited amount of time provided for preparation (observation, reconnaissance, preparation of combined arms cooperation) allowed by Army HQ negatively affected the quality of preparation and the actions of the tank units.

It is necessary to say that repeated attacks in one direction over the span of several days had no effect, and increased the amount of casualties, as the enemy had time to built up a thick wall of anti-tank guns. On the contrary, practice showed that hidden concentrations of tanks and then a sudden attack brings significant successes with almost no losses in materiel or manpower.

For example, the success of the Shal operation and the decisive penetration of the enemy defenses is explained by a sudden and secret reshuffle by the 16th Tank Brigade from the Pogostin direction.

When organizing such an operation, it is necessary to take into account all elements that may influence its success. In this operation, the poor condition of roads and passages through the railroad embankment for tanks could have sabotaged the success of the operation. My personal intervention and order to send tanks not through passages, but over the embankment allowed the start of the operation to commence on time, and did not let the enemy discover our movements in time to prepare an anti-tank defense.

Tank columns used in the previous months, 3-5 tanks per column with heavy or medium tanks in the front making a path for light tanks confirmed their usefulness in the forest. In this formation, crews can look after each other, cover tanks that are ahead, and sufficiently well guard their flanks.

Motorized infantry battalions, due to their organization and armament, are a powerful combat unit and must be used in combination with tanks in order to secure their successes and cover both the brigade in general and its units on vulnerable flanks.

2. Causes of large losses, aside from those listed in February, include:

Ignorance of terms from the Red Army combined arms manual, deciding tasks of infantry, artillery, and tanks.

Poor skill of combined arms commanders, demanding tanks to advance without preliminary suppression of AT guns and splitting tank units into small groups.

The main deficiencies when using tanks in a way that violates NKO order #057 are as follows:

Artillery support for tanks, in most cases, is absent, even though there is a point made in infantry orders about supporting tank attacks with artillery (311th, 11th, 281st, 80th infantry divisions).The guns directly accompanying tanks were not given enough crews, which caused them to constantly lag behind the advancing tanks.As a result of passive artillery, tanks had to fight enemy AT guns themselves, which were often firing thermite shells. As a result, there were large losses.For example, in the 122nd TBr, over several days of fighting alongside the 281st Infantry Division, 10 tanks were lost, 3 of them irreparably. 16th TBr, fighting alongside 80th Infantry Division lost a total of 6 light tanks without making any significant progress. 98th TBr was supporting the 4th GSK and over three days of battle (March 20th-22nd) lost 6 tanks permanently.

Tanks are still being used in small groups. For example, on March 24th-28th, 320th Infantry Regiment of the 11th Infantry Division used 2 tanks. March 13-14th, 1062nd Infantry Regiment in the 281st Infantry Division used 3 tanks, on March 16th, out of 8 tanks working with the 281st Infantry Division, 3 were passed on the the 11th Infantry Division. 12 tanks from the 98th TBr were assigned to the 3rd GSD and 33rd Infantry Brigade, which also split up tanks to give to its regiments. 3 tanks were assigned to support 115th Infantry Division.This kind of separation into small groups negatively impacts the organization of tank actions and does not achieve positive results.Aside from this, application of these small groups in one direction repeatedly over several days lets the enemy built up an anti-tank defense, and destroy these tanks, often irreparably.

There are cases when there is not enough time to organize the use of tanks after receiving objectives from Army HQ (agreement on cooperation, tank reconnaissance, observation, etc).As a result of this, tank losses grow.For example, when the 122nd TBr fought alongside the 219th Infantry Regiment of the 11th Infantry Division, three tanks were destroyed by enemy mines and explosives, when 16th TBr fought alongside the 281th Infantry Regiment of the 80th Infantry Division, hurriedly organized combat plans, poor knowledge of infantry commanders and little time allotted for reconnaissance, two tanks were destroyed by AT guns immediately when they arrived at their positions.

Lately, fearing that the infantry will retreat at night from a held position, infantry commanders leave tanks within the infantry camps overnight. As a result, tank crews spend several days in a row fighting, having no time to conduct technical inspections and preventative maintenance. This leads to excessive wear of tank parts and losses due to breakdowns.

A number of combined arms commanders' attempts to use tanks incorrectly was prevented by me personally. For example, Major-General Starikov wanted to send tanks into a night attack, Major-General Berezinskiy tried to send individual vehicles into battle. In connection to this, it is important to remind combined arms commanders about NKO order #057 and warn them about using and taking care of tanks in accordance with Red Army requirements.

Assumptions and conclusions made in the previous report about repairs and evacuations are fully confirmed in March. March experience shows that uninterrupted use of tanks in battle for several days does not allow for any thorough inspection of the tanks' technical condition and timely lubrication of its components, which leads to unnecessary wear on the tanks and mechanical breakdowns.

When tanks were removed from the brigade for service, the inspection of defects was often poor, and underestimated the amount of time needed to repair the tank. This led to low quality of repairs and rapid breakdowns of tanks.

There are not enough repair resources available. A repair company only has a small platoon of repair vehicles. Repair companies had to be reinforced with 20-25 specialists from Army repair bases and brigades sent from Leningrad factories.

Actions in swampy forests require engineering units in order to place roads immediately after advancing infantry. Without these roads, the transportation of fuel, lubricants, and ammunition for uninterrupted supply of tanks is jeopardized.

The political and morale condition of the tank crews and unit in general is high. Crews had to fight for days with little sleep or no sleep, spending nights among the infantry where they had to resupply their tank and, if possible, perform a technical inspection. Breaks of 3-5 days in the fighting did not give any rest to the tank crews, which had to work to restore their vehicles. Despite these difficult conditions, there were no cases of low morale or cowardice. The personnel act bravely and decisively, show initiative, and cause large losses to the enemy, leading to the failure of his defensive lines (Konduya, Shala, Zenino) and our units' successfully progress forward."

Wednesday, 25 June 2014

"Memo on the use of the single-shot flamethrower and pistol flamethrower on the T-34 tank.
March 3rd, 1942

A. On single-shot gunpowder flamethrowers.

Single-shot flamethrowers were developed according to the SNK decree #5830 from July 26th, 1941. Kirov factory, on its own initiative, promised to produce and install 250 flamethrowers on KV tanks in August of 1941 (military representative Shpitalov's report #703 file 9 p.25 1941).

Trials of single-shot flamethrowers on KV tanks (file 14 p.11 1940) were executed according to orders from Lieutenant-General comrade Fedorenko (file 120-2 p.13 1940 to #063 on August 5th, 1941). Trials commissions found the flamethrowers satisfactory and recommended their immediate production and installation on KV and T-34 tanks.In the first days of October of 1941, a document was addressed to Deputy Chair of the SNK, comrade Malyshev, saying that due to increase in automatic ATO-41, the need for single-shot tank flamethrowers waned. The document was shown to Major-General comrade Lebedev, and he agreed that the need for single-shot flamethrowers has passed.

As a temporary measure before the production of flamethrower tanks, high explosive flamethrowers on T-34 tanks and single-shot flamethrowers on trawls are used.

As the production of ATO-41 flamethrowers is delayed and HE flamethrowers mounted on T-34 tanks are heavy, clumsy, and uncomfortable to use, single-shot flamethrowers must be converted to be used on regular T-34 tanks. For this it is necessary to:

Remove the defects of single-shot flamethrowers mentioned in the trials acts.

Instruct the People's Commissariat of Tank Production to install 400 single shot flamethrowers on T-34 tanks in the second quarter of this year, specifically 150 tanks at factory #183, 150 tanks at STZ, and 100 tanks at factory #112.

No less than a month is needed for production of single-shot flamethrowers to ramp up.

B. On trench flamethrower pistols (TOP)

The automatic flamethrower design proposed by comrade Novikov is not novel. The proposed design is not worked out and is incomplete. For example, it lacks a receiver, air reductor, and valves.

The flamethrower pistol produced at GVHU KA is already mastered by production lines.

The weakest link of the system is the consumption of diesel vapours from the engine cylinders. The use of these vapours to reach a pressure of 30-40 atmospheres is complicated. These vapours contain oil and incompletely combusted fuel, which will reduce the reliability of the valve. Factory #183 engineers are at work on this issue, but no satisfactory answer has been found. The author proposes a diagram, and not a solution. He has no valve blueprints.

The production of a prototype using comrade Novikov's designs is premature. It is necessary to instruct the People's Commissariat of Tank Production to develop and test such a valve that would regulate the collection of vapour in order to produce the pressure of 30-40 atmospheres in a reservoir."

The ZiS-5 isn't the gun that went on the KV-1 and KV-1S, but an older index, referring to a 76 mm tank gun with ballistics of the 3-K model 1931 AA gun.

Another table, comparing the masses of only turrets, but for many more vehicles. The data is approximate, due to manufacturing tolerances individual turrets could end up heavier or lighter.

Vehicle

Turret weight (kg)

With turret ring

Without turret ring

Domestic

KV-1S

5300

5670

T-34 (76 mm)

2700

2890

BT-7

600

645

T-26

750

805

T-80

1250

1340

T-70

1000

1070

T-60

550

590

BA-10

450

485

BA-20

150

165

BA-64

110

120

Captured

Tiger

6000

6450

Panther

4700

5050

PzIV

3000

3220

PzIII

2000

2140

PzII Ausf. B

650

700

SdKfz 221

200

215

SdKfz 222

350

375

Allies

M3 Light

900

965

Churchill

3600

3850

Valentine

1400

1500

Matilda

3100

3320

M3 Medium

1900

2035

M4A2

3500

3750

M4A4

3500

3750

Sadly, these notes do not appear to mention what modification. Another document is provided stating the weight of the Matilda turret to be 3812 kg with the turret ring and 3567 without, with the same figured for the Valentine being 2415 kg and 2210 kg, significantly higher than the ones in the table. However, the latter figures count the gun mantlet, while the former ones presumably do not.

Monday, 23 June 2014

Driving a tank is not like driving a car. In order to turn, you do not simply turn a wheel, but must wrestle with levers controlling an engine with many hundreds of horsepowers, dragging a beast that weighs tens of tons. That is not an easy task. CAMD RF 38-11355-2884 (from litl-bro's repository) covers the forces involved in driving a T-34-85 and an IS-3.The span the levers travel was divided into 6 equal parts. Forces for the first 5 include only the force to move the lever, but forces for the last part include the force to bring the friction clutch into action and stop the tank completely.The first vehicle that is tested is a T-34-85 #381105 from factory #112 (Krasonye Sormovo). This tank travelled 1010 km before this test.

Lever position

Force in kg

Difference in kg

Right lever

Left lever

1

21.5

24.0

2.5

2

26.0

30.0

4.0

3

28.5

33.0

4.5

4

34.0

37.0

3.0

5

33.0

37.0

4.0

6

29.0

34.0

5.0

Now, for turning the tank in place.

Gear

Force in kg

Difference in kg

Turn radius

Right lever

Left lever

1

37

34

3

In place (180 degrees)

2

40

38

2

Same

3

40

39

1

8 meters (extrapolated from 90 degree turn)

Next is another T-34-85, #872024, from factory #174 (Voroshilov factory). This tank travelled 1002 km before these trials.

Lever position

Force in kg

Difference in kg

Right lever

Left lever

1

26.0

24.5

1.5

2

29.0

30.0

1.0

3

33.0

32.0

1.0

4

37.0

37.0

0

5

37.0

37.0

0

6

35.0

35.0

0

Gear

Force in kg

Difference in kg

Turn radius

Right lever

Left lever

1

42

39

3

In place (180 degrees)

2

46

44

2

Same

3

46

45

1

8 meters (extrapolated from 90 degree turn)

Next is a T-34-85 #664479 from factory #183 (HPZ). The tank was basically new, just out of factory trials, and travelled 100 km.

Lever position

Force in kg

Difference in kg

Right lever

Left lever

1

23.0

23.5

0.5

2

28.5

27.0

1.5

3

30.0

29.0

1.0

4

35.0

35.5

0.5

5

37.5

37.0

0.5

6

36.0

34.5

1.5

Gear

Force in kg

Difference in kg

Turn radius

Right lever

Left lever

1

38

36

2

In place (180 degrees)

2

44

41

3

Same

3

44.5

44

1.5

8 meters (extrapolated from 90 degree turn)

As you can see, the new tank does a little bit better.

Now, for the IS-3. The tank travelled 500 km before trials. The lever range was split into only three sections:

From the initial position to first position (the planetary mechanism friction clutch is off, the small brake belt is taut).

First position to second (brake belt of the stopper drum is taut).

Brake belt of the stopper is at maximum tautness.

Lever position

Force in kg

Difference in kg

Right lever

Left lever

1

32

30

2

2

16

16

0

3

30.0

30

0

The IS-3 is heavier, but more modern. As a result, driving it does not take more force than driving a T-34, and sometimes, much less force.

Lever position

Force in kg

Difference in kg

Right lever

Left lever

1

23.0

23.5

0.5

2

28.5

27.0

1.5

3

30.0

29.0

1.0

4

35.0

35.5

0.5

5

37.5

37.0

0.5

6

36.0

34.5

1.5

Now, for turning around:

Gear

Forces to move the lever from the initial position
to the first (smooth turn)

Turn radius in meters

Forces to move the lever from the first position
to the full position (turn in place)

Right lever

Left lever

Right lever

Left lever

1

30

29

14

25

25

2

29

27

14

22-35

22-35

3

28

28

15

20-40

20-40

4

26

26

15

18-40

18-40

5

24

24

Maneuver not performed

6

20

23

7

16

20

CAMD RF 38-11355-2890 contains similar measurements for a much larger set of tanks. The conditions for turning around are different: instead of a half-turn or a quarter-turn, tanks made multiple turns. The first turn did not count, and only the subsequent turns (where the mud that was removed by the first turn did not affect the trial) were recorded.